Engine unit for electrically operated thermogauges



J 1942- E. F. BACON 2,286,707

ENGINE UNIT FOR ELECTRCALLY OPERATED THERMOGAUGE Filed June 21, 1940 Snventor Gttorngs Patented June 16, 1942 UNITED ENGINE UNIT FOR ELECTRICALLY OPERATED THERMOGAUGES Elbridge F. Bacon, Flint, Mich, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application June 21, 1940, Serial No. 341,725

2 Claims.

This invention relates to temperature indicators of the telemetric type and has particular reference to the engine unit applied to the internal combustion engine of an automotive vehicle. The essential feature of the invention is the provision of a fluid tight seal to close the shell which is screwed. into the engine block.

The shell of the invention has its outer end open and an annular recess is formed in the shell end. In the recess a rubber gasket is positioned and a cover is placed over the gasket. The recess has an inclined bottom wall and in pressing the cover onto this gasket the gasket is compressed until the cover strikes the edge of the recess. The end of the shell is then spun or turned over onto the cover to make a fluid tight seal.

The cover has a central opening to enable an electric terminal to pass therethrough. In the opening surrounding the terminal a neoprene gasket is positioned and an insulating washer is positioned on the inside of the cover in an ofiset formed therein. The head of the terminal abuts against the inside of the washer. On the outside of the cover a second insulating washer is positioned, and over the insulating washer there is placed an iron washer and then a spring washer and a nut is screwed onto the terminal and by tightening the nut the neoprene gasket is caused to spread and tightly press against the inside of the opening in the cover and also against the 5 side of the terminal to form a fluid-tight connection.

On the drawing Figure 1 is a view of a part of an automotive vehicle showing the invention applied.

Figure 2 is a section through the engine unit and disclosing the fluid tight seal.

Figure 3 is a section on the line 3-3 of Figure 2.

Referring to the drawing, the numeral 2 indicates a vehicle as a whole. The vehicle has the usual roof 4, windshield 6, and hood 8. Underneath the hood there is the usual internal combustion engine It which has the usual oil pan l2,

the engine head 14, and the valve cover I6. The

clutch housing is indicated at 18.

At the instrument board 20 of the vehicle there is positioned the usual ignition lock 22 which will make or break the current from the usual battery 24. Connected to the circuit with the ignition switch 22 and the battery 24 there is a differential galvanometer 26 which is of the type illustrated in the patents to Bacon 1,791,786 or Schwarze 2,139,385, 2,139,386, and 2,178,108. From the differential galvanometer 26 the lead 28 connects with the engine unit 36 which is secured in the engine block at any suitable place.

Referring to Figure 2, the engine unit 36 is shown as having screw threads 32 which screw into a correspondingly threaded part of the engine ID. The unit 36 comprises the shell 34 having the integral imperforate bottom 36. In the hollow part of the shell the cylindrical insulating element 38 is placed and in the bottom of the shell is a. copper button 46. Over the copper button there is positioned a resistance element 42 of the type shown and described in the patent issued to Randolph and Bigler, 2,197,115 and in their application S. N. 204,703 filed April 27, 1938, now Patent 2,273,991, issued Feb. 24, 1942. A coil spring 44 acting as an electrical conductor is positioned between the resistance element 42 and the terminal stud 46. The stud 46 has a head 48.

The open end of the shell 34 is provided with an annular recess 56 the bottom of which is inclined as is best shown in Figure 2 and a sharp edge is formed at 52. In the recess 50 a gasket 54, preferably of rubber, is positioned, and over the gasket there is received the edge of a cover 56. The cover is pressed tightly on the gasket 54 to compress it into the recess 56 and the compression iscontinued until the inner face of the cover strikes against the sharp edge 52. The extreme end 68 of the shell is then turned or spun over onto the edge of the cover 56 to make a fluid tight seal between parts 52, 54, and 56.

The cover 56 is provided with an ofiset 63 which forms a recess on the inside of the cover and inside this recess the insulating washer 62 is received. The insulating washer is positioned between the head 48 of the terminal 46 and the inside of the cover 66.

The cover has an opening to allow the terminal stud 46 to pass therethrough and in this opening there is placed a neoprene gasket 6 On the outside of the cover and over the cover 56 and the neoprene gasket 64 there is positioned a washer 66 of insulating material and over the washer 66 there is positioned an iron washer 68, while a spring washer I6 is placed over the iron washer 68. The terminal stud 46 has its exterior screw-threaded as indicated at 12 and a nut 14 is screwed on the threaded part 12 and by tightening the nut the parts are all drawn together. The neoprene gasket 64 is a little thicker than the cover 56 and has a tight fit in the opening in the cover. When the nut 14 is tightened the compression between the insulating washers 62 and 66 will cause the neoprene gasket to spread and fit tightly against the inside of the opening in the cover and against the terminal 12 to make a fluid tight connection.

The exterior of the shell 34 preferably has a polygonal shape as indicated at 16 in order to enable the application of a tool either to tighten the shell into the ends of the engine block or to release it therefrom.

I claim:

1. In a seal for an engine unit of an electric telemetric temperature indicating system, a hollow shell, a recessed part in the end of the shell, a gasket positioned in the recessed part, a cover positioned over the recessed part and over the gasket, a bent over edge on the end of the shell to hold the cover in place and form a fluid tight seal, said cover having an opening at its center, a gasket in the opening, two insulating washers, one washer on each side of the opening and overlapping the cover, an electric terminal passing through said washers and cover, and a nut screwed on the end of the terminal and tightly pressing the washers and gasket together to form a fluid tight seal.

2. In a seal for an engine unit of an electric telemetric temperature indicating system, a hollow shell, a recessed part in the end of the shell, a gasket positioned in the recessed part, a cover positioned over the recessed part and over the gasket, a bent over edge on the end of the shell ELBRIDGE F. BACON. 

